Some of the leaves of my Java fern are getting brown spots on the back of
them. Each spot is about 1/8 inch in diameter, and 1/16 inch high. They
appear in 2 uniform rows down the back of the leaf, one row on each side of
the main "vein" running the length of the leaf. They are fairly well
attached to the leaf, a rough flow of water or light brushing with the hand
will not remove them, but they come off without too much trouble with a
fingernail. On an otherwise healthy plant only a few leaves have these
spots,and the ones that do have the full 2 rows the whole length of the
leaf - there is no in-between. Anyone know what this is and/or what causes
it?

--
Scott Nichting